Benchmaster, Master of Benches: a Robot Trap Shop Tale

You know, I told myself I’d take 2020 as a year to learn to relax, reflect, and stop building everything all the time because we’re all going to die soon anyway. And then I had to try and remember everything I did just since late September to write the last post. But there’s more, as in that post, I neglected all of the shop-building I’ve still been on a quest to do.

For one, I’ve been seeking a milling machine to accompany tinylathe (which does need its own writeup), but not needing one for business purposes, I wasn’t keen on buying a tinymill new. I kept an eye on Craigslist and Zuckerburg’s Emporium for good deals on small to medium sized mills – while I could have easily bought Bridgeport sized machines for days, that violated my rule for the time being of No Multi-Thousand Pound Objects That Can’t Drive Themselves.

My other constraint was no round-column mill-drills. I know they’d get the job “done”, but I can’t stand those things because of their propensity to rotate on the column and lose all your zeroes for you. So really I was just sitting on my ass waiting for “The One”, and was close to being able to get a few Grizzly mid-sized mills with square columns (and similar)… but damn, it turns out other people also want them, and they went quickly.

Luckily, fellow robot builder and machinery enthusiast Alex Horne made me an offer that I found very hard to refuse – on my way to Boston last November to obtain Overhaul 1 Among Other Things, I picked up this little guy from him.

Huh. Well that’s cute. It’s like a larval version of the classic American heavy manual mill pattern, like the first instar stage of a Cincinnati or Kearny-Trecker. I loved it.

The travel is about 12″ x 6″, which is pretty impressive. It’s in a similar size class as the Seig X2 type “tinymill” that’s sold everywhere, but built like a battleship. This was a difficult two-person lift, where as I alone can chuck a tinymill-sized machine onto the workbench back at MIT.

So I’m barely 2/3rds of the way to Boston and already have picked up several hundred pounds of junk. Well this trip is certainly going well! The mill came with this very heavy work table which itself was another hundred pounds or more of very dense and nicely finished Old Wood topping a frame made of 1/4″ thick steel angles.

We stopped by a local machinery dealer which I keep calling Hank Hill Machinery or Hillbilly Machinery to inspect their wares, and ended up finding a small treasure trove of full drill/mill/tap organizers. I spent even more money I didn’t intend to in order to swipe these – we made a “What if I took all of them” offer and split the goods afterwards.

So after I got back home and unloaded…. what on earth did I just buy. This is how I operate, as you know. Obtain first, figure out what it is you got after the fact. I’m literally the most advertisement-agnostic person on the planet. You can’t egg me on to buy something through viral targeted marketing, but you can set your product out so I trip over it and bring it home, then I’ll do research on how to buy more and subscribe to your services.

This adorable neotenic critter is a Benchmaster, made by a company called Duro that eventually just became “Benchmaster”. The product? Benchmaster. What does it do? Be the master of benches.

Picture shamelessly stolen from Lathes.co.uk, so go visit them.

It was, as it seems, targeted at the hobbyist or a ‘second machine’ type situation. Sounds like a limited market, but they aren’t as rare as I thought they were, and an enthusiastic community exists around them where people have done comical swaps such as putting a Bridgeport M-Head on the damn thing.

If I haven’t beat this drum enough, I’d like to reiterate a point I made when I posted about crabmower: I bought an old, obscure device without knowing what it was, and someone had made an entire page on how they fixed up and modified it. Folks, this is why we’re here.

Alright, I now had to find a home for the Benchmaster so it can be the master of a bench. Ever since I built the benches, I’d already earmarked half of one of them next to tinylathe for the installtion of a mill. It had recently become occupied by random sanding/grinding tools and Overhaul parts, so there was a lot of cleanup and displacement to do.

Namely, all of my tooling (the stuff you need to USE a mill and lathe) had to be displaced. I therefore was forced on a hunt for new tool organization, which will come later. For now, it’ll just live in a pile on the floor like my soul.

I decided to disassemble the original heavy wooden bench to form a foundation for the mill. The 1″ of OSB my benchtops were made of felt just a bit too flexible for it to be a good anchor, so the plan was to secure the big wooden block to the bench, then bolt the mill through all of it.

The interesting thing about the Benchmaster is that the knee leadscrew pokes down from the mill by a fair amount. That’s why they always have to be on stands. I decided to drill a 3/4″ hole through everything as the leadscrew sphincter

#OSHACrane was used to line everything up and set the machine into position…

…upon which I lined it up with the marker lines I had drawn, then drilled through and bolted in-place.

And here it is, the menagerie of miniature machinery.

Alex threw in the 4″ milling vise, which we both agreed was way too large for this machine. It used up a significant amount of the Z travel just for itself, and this mill doesn’t have a quill (A bit annoying, and a good excuse to do a head swap later on), so its usefulness is severel curtailed. With the thing finally installed in place, I gave everything the ol’ lube n tune, taking the axes apart to adjust the slides and leadscrew nut tightness.

But damn is this thing rigid. Being made back when America was Great, Men were Men, and Steel was Free meant it’s exceptionally smooth (once I tuned the gibs in and cleaned & oiled everything) and I dragged this 1/2″ endmill at 1/2″ DOC through my sacrificial aluminum test piece at the highest spindle belt speed, and it barely flinched. This is a suicidal cut on a Seig X2 class mini-mill, and even if you did manage to do so by feeding slowly, the finish would have been chattery.

For now, until I want to get a 3 inch milling vise, I bestowed upon it my old toolmaker style vise that usually held motors under testing.

The other downside is at the moment it doesn’t have digital scales, so I’m back to using a lot of my “vernacular machining” skills learned years and years ago. My “edge finder” is really just putting a 1/2″ drill rod (itself really a cut-down, destroyed 1/2″ drill bit) into the collet and bumping off.

It fulfills my current “mill” needs quite well either way: Flat this shaft, key this, shave that down, bore this out. Anything substantially complex right now I have enough contacts and favors to call in so I can have a part made. I’ll be planning to add digital scales soon, and I’d like to eventually see if I can get it a quill via head swap or severe head modification.

More About the #RobotTrapShop and Building Up a New Workspace

While writing my previous post about moving back South, I decided that there was enough content about putting together the garage workspace to warrant its own post. You see, this is really the first time I’ve ever really built up a workspace for myself only. I’ve built up and operated/managed quite a few facilities now, and even if it was “my shop” in the sense that I oversee and get to use it a lot, it still was always shared.

There was my time at MITERS, the MIT student makerspace – then upstairs in my research group the MIT International Design Center. Then another shared workspace at the old mill building we called “The Mochi Palace” prior to it being converted over for company use.  I suppose there was Big Chuck’s Auto Body over the spring and summer, but that was a very temporary and focused setup. My hope is this shop will be in place – or at least travel with me – for a few years yet.  But I’d be lying if I said that brief taste of having a workspace that was just mine and wasn’t critical to the operation of something else, or had to be kept up in appearances for somebody else’s tastes, didn’t influence my ultimate decision to seek less costly pastures.

First, before we get to the shop, though, we gotta talk about The Move:

I’d already containerized my life pretty well due to the somewhat frequent moving of shops in the past few years, so I just continued ordering more of the same sized 27″ totey-bins. The FIRST Robotics branded ones date back to the “Recycle Rush” game a few years ago and were picked up for real cheap. This meant that beyond loose large automotive tools such as the engine crane and errant van parts, the move was quite well coordinated. What I didn’t get into totes got put into some large cardboard boxes left over from company-received shipment (e.g. of toolboxes and big plastic tanks among other things).  The 16 foot Uhaul truck was filled to about 4 feet in front of the door, which was earmarked for furniture.  This whole thing was tied up in the “web of lies” formation shown above, as we nicknamed it.

While I’m not that big of a stickler for organization, it was a good time to take account of everything heavy that I owned, and I actually sold off a lot of stuff on eBay over the fall months that more or less funded the entire move! Hurray!

First order of business: Puke everything inside the garage and deal with it later!

 

Couple days in and I’m working on setting the shelves back up, at least, so I can start throwing totes and robot parts onto them.

I also decided to just spend a weekend in early January and build myself some workbenches. I spent a while scouting Craigslist, classified ads, and equipment dealers, but wasn’t really finding any ones that looked good in the quantity I was hoping for. There were some, but I’d basically be buying new anyway costwise (Then I’d just buy new). So instead of dropping like $1000 on workbenches when I can blow on Overhaul instead, I decided to spend $100 at Home Depot and knock these out. I made two 3 x 8 foot benches in the “usual” hobbyist style – for some reason, basically every workbench I’ve seen be handmade is made this way. Guess it’s a pretty solid design for the effort involved.

I also made a rolling table for Overhaul and eventually other projects, just the same method but with the legs cut short so I could put it on a set of total-locking casters, and have it be…

…equal in height to the benches for easy transfer of things on and off!

Overall I was quite satisfied with the “Majority of 1 Saturday” work and cost. My only regret? Using the OSB as a top. I might skin it in hardboard or MDF later on. The tops are double layered 1/2″ OSB – nice and sturdy, but don’t run your hand across it. I coated the edges with some left over spray-on urethane I brought down, which lowered the splinter factor somewhat.

 

By mid-January, it’s almost looking like a functional workspace! I noticed there was a light fixture with a broken bulb up above the lower set of rafters, so I decided to get a gigantic 100W (actual!) LED “corn cob” light to put up there. It really lights the place up, but casts strange shadows due to the rafters.

I ordered extra shelves to unpack Big Chuck’s Auto Body and also finally give my screw collection a home.

 

When the opportunity presented, I also went on tool runs based on findings from Craigslist, Facebook Marketplace, and the like. I managed to land this ‘vintage’ Craftsman bandsaw for only $100. I was out to get a vertical bandsaw to at least be able to cut most sheet materials to make stuff if need be, and wanted to avoid getting a chintzy small one. This Craftsman was the perfect size – I could wrestle it around, but also trusted it was solid enough to do actual work.

 

One cheeky change I made though, right after getting it, was re-gearing the saw through its belt drive. It was definitely a wood-cutting bandsaw by intent – there’s only like a 2:1 ratio between the motor and the blade wheels. I changed this to a roughly 4.25:1, halving the blade speed. Once I put a 14 tooth variable-pitch bimetal blade on it, this thing was basically unstoppable in aluminum. I tested cutting a 2″ wide bar through its width (i.e. a 2″ depth of cut) and it was handled admirably. Just can’t do steel on it, since the blade speed is still much too high- I’d have to put a back gear on it or something to be able to cut steels.

In early February now, and I’ve basically set the space up for Overhaul work. You can see another Craigslist acquisiton to the left – the 3-ton size arbor press. I haven’t given it a permanent home yet, but it just gets clamped to whatever bench I need to smash something on.

Rewinding a bit back to the week of move-in… one of the first things to go up is the 3D printing station and Equals Zero shipping area.

Later on, I found this table on the damn sidewalk while driving home one day through the back residential streets. How quaint! Good thing I only have vehicles that can convey large volumes of stuff. I gave the top a quick sanding and oil coat, and here we are – supplemental shipping/assembly bench or electronics area.

Check out the row of Equals Zero stock shelves in the background. I found a “local minima” price solution that was ordering a certain Home Depot shelf size online (picking up in person) and then ordering a certain set of casters on Amazon. There’s more of these now, actually.

Speaking of which, I also handed Jeff Bezos some money to dress out this corner as an EE station. Hopefully I’ll pick up more instrumentation too, relatively soon! Right now it’s enough to put together Ragebridges and whatnot, which is all I need it for.

Obviously these facilities will evolve as I need them. For now, they’ll carry me through most of the projects I think I’ll get up to, and allow some basic consulting work to happen too. There’s the unfinished basement which is currently very underutilized because it’s not climate controlled and tends to be a bit moist and drafty – not a good environment for 3D printers or electronics. I currently have it just as cold storage, but might move more things there such as the van parts shelf if I end up collecting more tools.  But here we are! Welcome to the #RobotTrapShop.

Reassembling a Bridgeport J-head with Uncle Charles! And More About Hooking Up Your Annoyingly Chinese VFD

You know what? I’m tired of having sweet-ass machinery sitting around not hooked up. Last time in “Charles takes forever to set up his own shop because he’s sick of setting up shops”, I did some battle with a generic Chinese VFD and completed what the damn factory couldn’t be buggered to by adding the dynamic braking components.

Though Bridget ( <3 ) ran since then, there were some issues. The spindle brake was so worn it was difficult to change tools, and the head made the “Bridgeport Clack” from the high/low speed dog clutch being worn. The motor’s V-belt was also severely worn. I wanted to tear it down for a rebuild of sorts, so I spent a little while watching “How to rebuild a Bridgeport head” videos. I decided that all of these videos sucked, and that I was really only interested in repairing the brake and replacing the timing belt and V-belts.

So here is my documented take on how to take apart a Bridgeport 1J head. In it, I discover that it wasn’t as terrifying as I had thought originally, and that old-school American engineers might commit some abominations but damn they’re good abominations. I guess this is kind of a Beyond Unboxing, too.

Step 1: Dismount the motor, which is retained by two studs, one with a set of two jam-nuts to let it move a little for belt tensioning, and another that’s the ball handle (you unscrew the ball handle and then untighten what it’s attached to). Then, crank the head about the Y axis (roll) 90 degrees.

Six socket head cap screws live underneath the belt cover casting and retain it to the steel back-gear housing. You can take all these off; pins retain the belt cover afterwards, and it needs to be yanked off. Don’t worry, it’s not heavy. But there’s one catch:

The back-gear timing belt pulleys both have flanges. To remove the belt cover means taking off one of the pulleys with it, and that means removing the belt with it. You have to remove the four slotted head screws that keep the pulley flange on. Once it’s gone, the belt slides off with everything, like this:

This setup is quite the abomination. The timing belt has no tensioner – it relies on good will and good spacing. Mine was getting a little loose from the years. While I haven’t run the machine hard in back-gear range to see if the belt skips, I ordered a new belt anyway since it’s a “Might as well” item. The belts, and other rebuild components which will be seen, came from H &W Machinery Repair.

While the cover was off, I cleaned off the thick layer of congealed rubber dust and spindle oil. I didn’t break into the back gear cavity, however – if you do, remove the nut on the big pulley and use a gear puller or Three-Phase Prybar to pop it off, then undo the remaining screws. Some times the gear cavity is filled with grunge; if your machine had multiple owners, chances are it has both grease and oil in it.

I loosened the cover and a lot of remnant oil started pouring out, so I’ll likely keep it together but drown it through the front oil port later.

The second step pulley and back gear timing pulley live with the belt cover and has a large bearing carrier assembly under it. To undo this, I need to remove the shifter mechanism.

The pins that ride in the shifter groove also help retain it completely. Problem: One of them was completely stripped and wobbly. Due to the pressure exerted by loading springs underneath the pulley, I couldn’t get the pin to bite on its remaining threads and back out. So I drilled straight down the center and threaded the hole for a #4-40 screw that I could then grab with pliers and pull on:

The stock machine has slotted head pins; H&W sells a replacement with a hex wrench drive. Here’s the victim screw driven in…

And a few tugs later, the shifter ring is freed.

The pulley then flies off the other side, since there are loading springs underneath it.

And here we have the brake assembly. The brake is simply a phenolic drum brake setup that crams against the interior of the pulley. Nothing sophisticated at all!

To remove the brake, you have to remove the 3 slotted-head shoulder screws holding it down. However, to do that, beforehand you have to undo the three hex nuts on the top side (underside in these photos) – they prevent the shoulder screws from loosening.  After that, the brake can be wiggled off gently. It will snap closed, due to its own return springs, so watch your fingertips .

The small tongue on the upper right of the bearing bore is the cam that toggles the brake shoes.

Many times, when a Bridgeport spindle brake is worn, it means two things – one, that the brake shoes are worn down, but what I found is that the cam had also dug a little trench into the brake shoes where it makes contact. So this has reduced the effective travel length and caused the brake shoe to lose engagement. In fact, it seems like the harder you wail on the brake lever, the quicker you induce this 2nd failure mode.

Also, Brigeport brake shoes are expensive. Speciality exotic part, sure, but I can do all 4 brakes on Mikuvan for less money using nice ceramic pads too! So I wasn’t going to replace these, but simply make the cam bigger.

Returning to the top side, the brake cam escapes if you untighten the set screw holding its handle pin in place. The pin slides out and the whole thing falls apart.  The cam and shaft assembly are on the upper right.

The fix? Make the cam bigger by welding repeatedly over it, building up more metal, then sanding and filing it down! This was after the rough-sanding stage. I filed a gentle round onto the engaging edges so it doesn’t cause further erosion of the phenolic laminate brake shoes.

Alright, we’re now on the reassembly path. The brake cam is going in back in…

Secured up top, along with installed brake shoes and re-tightened locking nuts.

I reassembled the shifter ring after cleaning the whole area and thoroughly greasing it. In Bridgeport maintenance, you’re supposed to oil the shifter ring daily in production use. I think I’m fine with putting in a few greasewads where it needs to be instead of having to clean up even more crusty oil grunge down the line.

The belt cover is remounted now.

Before final assembly, make sure to thread the timing belt and V-belt back onto the pulleys. Then as you line the belt cover on, wiggle the timing belt onto its large pulley.

When finished, you can then replace the small screws and pulley flange.

Putting this motor on was the precarious part, since it involved holding something pretty heavy and wiggling it from an awkward angle! I threaded the two jam nuts onto one side in order to hold it in place for….

Final head tilt. Here are the newly installed parts! And there we  have it. Shifts great, runs smoothly. Still makes The Bridgeport Clack, but further research showed me that is all in the quill spline drive and there is not really a way to R&R that short of replacement. I’m fine with it.

Moving onto controls! I can’t use this thing from a potentiometer dangling by its wires forever. You may, but I have standards.

I put a little money on eBay into some more machine style switches and buttons.

I had two buttons left over from a project long ago, so they were going to be used as the Run and Stop functions. The same potentiometers got transplanted into a panel mount which I screwed into the housings. Knobs were a matching pair (rare! legendary!) found at MITERS.  The two-position switch will control forward vs. reverse.

The wiring was concocted using disembodied Ethernet cord, which is one of my favorites for pirating cables from their intended purposes. The VFD’s Use of Manual™ just showed a bunch of normal looking switch symbols connected to the forward/reverse, start/stop/reset, etc. inputs.

This is where I discovered another great undocumented feature of Use Of Manuals. The diagram was a lie, but only enough to get you in trouble.

I had problems with it accepting my switch configuration. I found that the VFD didn’t want to read my stop button at all, and it accepted any flip of the direction switch as a “run” command. That is, I can toggle the forward-reverse switch for it to change directions, but it wouldn’t take my stop button input. I’d have to hit the STOP button on the control panel of the VFD. After that, I couldn’t start it by using the start button, but just changing the state of the direction switch would let me turn the knob and increase speed again. Well, all of my settings seemed to be correct for the job, so I was a little confused and figured there must be Undocumented Behavior. This was certainly inconvenient to use the damn thing intuitively, and I certainly wouldn’t let anyone else touch it in this condition.

It took a few friends with experience in industrial controls to point out what I was doing wrong.

 

That is a diagram for a normal industrial magnetic contactor, showing how Start and Stop buttons are typically wired. In these things, the STOP switch is always closed unless something causes it to open (either by accident or on purpose). The Start switch, on the other hand, briefly powers the contactor coil which pulls in not only the main contacts, but a little auxiliary contact that keeps the coil energized and hence the contactor latched. You can see how any number of interlocks (e-stop systems, overload detection, etc.) can work its way into the STOP circuit and turn the machine off when needed.

The VFD is technically designed to replace this setup, so it’s expecting the Stop button to be normally closed. Well, all my switches are N/O type (close when pressed). So the VFD was waking up in an unexpected mode, I guess, where it seems to default to treating any forward/reverse switch inputs as “Okay, start running”. Well this seems a little scary of a failure mode.

Anyways, the Use Of Manual shows all switches as N/O, so it definitely assumes you already know industrial control practices to use it. That’s another endearing characteristic of Chinesium… you better know exactly what you’re searching for, or else you might find it.

Well that’s quick fix. I didn’t order modular contacts with my switches, but luckily they’re manufactured modularly enough to use the same set of contacts, just internally turned upside-down, to become N/C. Now my control panel works as expected – the stop button puts the VFD into slow-down-and-brake, then start will ramp the motor back up to the previous speed it was at. In run mode, I can change speeds at will, including braking down to zero speed manually.

And here’s the test video.

Now that I understand this setup (or do I….), I can build the second control box accordingly. It’s also easy now to add an anti-face-eating emergency stop mushroom button anywhere in line!

The next machine to go online will be Bridget’s cute Japanese friend, Taki-chan!

how about no

A New Beginning, Episode III: Revenge of the Charles

I’ve been doing a lot of these posts lately, it seems. Just last year, after departing my shopmaster/instructor position with MIT and hence no longer having a workspace there, I moved in to the Artisan’s Asylum, a local makerspace (which also happens to be the largest makerspace in the USA, founded and run for a while by the now creator of MegaBots). Now, barely over one year later, I’ve moved out again…

T H E   E Q U A L S    Z E R O   D E S I G N S   &   G R E E T I N G S   C O M P A N Y

…into something I can finally call “the shop”. God damn, remember when companies had REAL NAMES that didn’t sound like a syllable uttered while asphyxiating a small animal?

It’s about fuckin’ time. The hankering for workspace had reached a crescendo over the past few months between myself and Adam, my long-time partner in hood rat stuff & bad things, also now captain of Team Brutus. My recent contract projects have been bringing me newer, more interesting, and most importantly BIGGER work, and facing the prospect of having to also work on Overhaul again in a few short months (#season3), Artisans was becoming impossible. On the other hand, Adam has simply been making do without a permanent base camp for a while. Given both our proclivities and the rapidly rising prices in the area, it was another now-or-never scenario.

 

The building: a former clothing & sportswear factory which the company sold to new owners intent on eventually developing it into MOTHERFUCKIN’ CONDOSDO YOU PEOPLE NOT. HAVE. ENOUGH. CONDOS AROUND HERE OR SOMETHING? I digress. In the mean time, which means the next few years as they figure out exactly how ugly to make the new block o’ flats (that building being my local benchmark for ugly as fuck and overpriced construction) they’ve divided up the former factory floor into a few smaller parcels to function as rentable studios or offices, one of which fell into our lap. You can tell I really love the new property development trend in this area.

It’s on a typical “New England First Floor” – which means floor 1.5, with the basement halfway down. and us halfway up. So, no driving vans in, but direct freight elevator access to a real loading dock 6 feet below. In other words, just enough to be a pain in the ass and just good enough otherwise for me to deal, as the world likes it. The inside is stupendously large for both of us who have been conditioned to think that working butt-to-butt in a shared shop with Isaiah the Last Indie Wirebender is natural and acceptable. Nothing against you wire art, Isaiah, but my robots have tried to consume your workpieces several times while I was machining, and they’re really reaching their rebellious stage lately, so it’s better for both of us.

It’s ~2,300 square feet when finished – shown above is pre-construction of interior walls – putting it right about the size of MITERS. The multi-layered heavy wooden factory floor is finished in a classic “Inconsistently Leaking Machine” fashion sure to fetch thousands of hipster Bitcoins per month in the future when it becomes someone’s hotbox closet floor ,because weed is gonna be legal real soon now in Massachusetts! Oops… I mean #MakeAmericaStonedAgain-chusetts

With the beginning of the new shop space, so shall my Artisan’s Asylum presence come to a close. Luckily, most of my life is containerized. Not only did I count on having to move relatively often, as long as I didn’t own the whole damn block I was working in, but having stuff in nicely labeled containers appeals to my inner Jamie Hyneman greatly.  I bought a dozen more totey-bins (which by the way are called ALCs, or Attached-Lid Containers, but searching TOTEY-BIN returns the correct result on Google Images!) to more finely divide some of my parts since they would otherwise get too heavy.

By the way, it’s been physically verified that Mikuvan can contain 24 of these things – 26 if I use up the front seat.

As with moving out of any space or building or home, taking a look back once you’ve restored it to the condition you found it is a little somber. Alas, great adventures lie ahead! Onwards, through the skies, and across the seas… also over a few curbs, because 26ft box truck. You know what? Driving a truck in Cambridge ain’t so bad! You just BIG your way everywhere you want to go! Want to turn left? FUCK YOU! Want to merge onto Route 28 during rush hour? FUCK YOU TOO!  Uber driver? FUCK YOU SPECIFICALLY IN THIS FASHION!

 

The robots in their new homes, free to frolick in the open pasture… oh, none of them currently work? That’s too bad.

 

I picked a convex corner to slowly grow out of. While we have a “space plan” this is the two of us we’re talking about here, so everything is really coming together somewhat organically as needed, so long as it is vaguely understood to resemble some plan, if interpreted selectively. In other words, #yolo.

My former “workbench” at Artisans is made of a 60″ wide wire shelf, and it will become the new 3D printer farm and shipping center for Equals Zero Designs. Not shown here is a collection of Craigslist workbenches that appeared in the space some time later in the week.

As luck would have it, the IDC was getting rid of its original-issue fixed desks and cubicles to make space for more researchers. The large office desks that were a familiar sight in my build reports from 2012 onwards were going to get replaced with smaller, more portable tables. So what’s gonna happen to them?

They end up with me again. The corner I was in was the first to get cleared. While the desks were taken apart and shuffled, there is a very high chance that my former IDC desk is now in our new shop, another somewhat fitting and poetic closing of one of life’s little loops.

A photo taken later in the week of moving when the benches have been arranged and the IDC tables have been erected again. Notice that they’re a little crooked. They did depend on the cubicle divider walls for structure, which were not part of the deal. I might add some additional legs or some bracing to the desk later. However, for seriously heavy-duty work like “I am putting my laptop computer here”, along with EE work, they’re fine as-is. In fact, the widthwise span has already been set up as my EE bench as of the now.

Charlesland fades into Bercustan as you move rightwards above, with the border lying somewhere on a 3D surface defined by the location of the last series of hand tools we borrowed from each other. I’m going to build a wall of lipo batteries soon and make Adam pay for it.

Now, no new workspace that we have anything to do with is complete without….

hella

new

toys

Oh my god. Holy Megabutts. What is this? Did I just buy a LATHE AND A MILL? Not even a Tinylathe and Tinymill!  A honest-to-Baby-Robot-Jesus Brigeport Series 1, and a Takisawa 14 x 30 TSL-800D toolroom lathe. HEY EVERYONE I HAVE CHILDREN NOW. MY POOR LIFE DECISIONS ENDED IN ME HAVING THINGS WHICH NEED CONSTANT UPKEEP AND PURCHASING OF EXPENSIVE ACCESSORIES ON A REGULAR BASIS AND WHICH TETHER ME TO ONE LOCATION FOR YEARS UNLESS I WANT TO SPENT A LOT OF TIME AND MONEY MOVING THEM!  

My children weigh 4,600 pounds combined! Don’t you dare call them fat,  you droplet of coolant curdle!

Getting these two machines – the result of an industrial auction – is a worthy post by itself, and we learned a lot about rigging and moving heavy things that week. There’s quite a few resources on the Internet from people who have documented their own DIY machine moves, so I will gladly contribute to it. Let’s just say it involved….

 

 

 Don’t look at me, I wasn’t driving.

So what’s next? I’m basically moved in and have been hacking at things for a few days now. Ongoing facilities improvements will occur – such as moving the machines to their final spots where power will be run to them. I’ve been kept busy by contract work for most of this fall so far, but #season3 is on the horizon and I have some new and exciting content for the Beyond Unboxing series coming up soon, not to mention Brushless Rage development.

Loose Ends and Tag Closing for Bits of October: Site Updates, Chibikart and Mini-Jasontrollers, New Expensive Things!

Now that the season of Dragon*Cons and Maker Faires and everything else has finally settled down, I’ve reached the curious state of having nothing to do with my life, being between large builds in much the same way you’d be between coffees or meth hits. My day to day activities revolve around managing the IDC (excuse the cheesiness) fabrication facilities, of which there will be some updates shortly, and monitoring & mentoring the classes running in the center, including the renowned How to Make a mess out of Almost Anything. I’m not a TA for the class per se, but part of the process of making sure the shop isn’t lit on fire is some times giving extra attention to those who would be most likely to do it.

That isn’t to say that my life is entirely empty and devoid of meaning. I’m tending towards taking the downtime to fix up my eternally problematic go-kart children, starting with Chibikart2. During some hard running at the Powerwheels race, I lost one of the Jasontrollers to Sudden Jasontroller Death Syndrome, a fairly common failure mode for them when they are over-run. The failure is always gate drive destruction since the circuitry is so fragile, and always not worth repairing to myself because it involves replacing so many small shitty transistors. Next up on my list after this is probably to add the electronic solenoid shifting to burnoutChibi and finally get rid of my super-rigged cable linkage. I’ve also been collecting many prospective parts for the “Chibi-Mikuvan” project, so stay tuned for a massive Beyond Unboxing the likes of which have never been seen!

But first, by popular request, I’ve added Pad Thai Doodle Ninja and Colsonbot CAD files to the References page. PTDN’s files are only made of 3D printable frame parts, but Colsonbot is the full bot – you’ll need Autodesk Inventor or a compatible viewer for anything but the STL files. All of the details on these bots are available in their respective build threads.

Onto Chibikart’s controller update. Like the dual controller mount I made for BurnoutChibi, I designed up a two-mini-Jasontroller snap-fit mount which also holds an 80mm fan. Essentially the same idea of BurnoutChibi’s. I was planning to current-hack these controllers to 40A, and for sure they will need supplementary air cooling.

 

The mount was printed on my Up machine, and this is about the largest object I’ve found it can handle reliably. It came out well, with minimal warping. I sincerely recommend the Up (now on 2 Plus!) to anyone thinking of getting a small hobby-class 3D printer.

Short of popping it in the Dimension, the Up is my go-to for structural parts. The ABS formulation they use is a higher hardness/toughness than the soupy generic stuff you feed to RepRaps and Makerbots. I was concerned about the snap fits being too aggressive and snapping off themselves, but they turned out to be just on the side of the acceptable line.

The mini-Jasons were cleaned up of unnecessary wires, leaving only the motor phases, power, the Hall sensors, throttle, and the ‘regen brake switch’ which may or may not be wired in in the future. The regenerative braking on these things is a fixed low current on-off kind of affair, so it’s not very helpful.

I plucked the 80mm case fan from stock – there’s nothing particularly special about it.

In the past, I’ve current-hacked these things with a blob of solder on the current sense shunt, but it’s such a bad hack and is unreliable – I’ve actually had the blob melt back off before. To remedy this, I began looking for large current shunt resistors packages that fit in between the leads of the existing shunt. This is the result – for a mini-Jason, a “2818” (.28″ long, or so) package current sense resistor is a nice fit. One that is 8mm (“31xx” – “35xx”) will fit even better and not require much solder bridging would fit better, but I could not find any that were not also square in shape – rectangular, the long way, is preferred.

I actually had this hack vicariously tested by Daniel (YAMEB) a while back. These shunts are 5 milliohms (not 10 – I measured erroneously the first time), so it took a nice sandwich of 10 milliohm resistors to get my 40 amps. The exact part number I used was WSHA-.01CT-ND, and it has a 5 milliohm brother in the form of WSHA-.005CT-ND.

I cleaned up the floorpan of Chibikart after removing the old Jasontroller – it was positively disgusting and filled with 2 years of floor grunge buildup, plus mud and dirt from running at two slightly wet Maker Faires. The new installation drops right into where the old controllers used to sit, after redrilling some mounting holes.

Systems wired back up. The first test drive was without the fan hookup, and without the sensors connected.

To rehash, these controllers “self-calibrate” sensors if you connect them and then run once to full speed. I couldn’t achieve this on the ground since the vehicle never really reaches “full speed” in the space available, so I had to freewheel it, being mindful of the 4700rpm-ish commutation limit. After one power cycle, the controllers had learned the sensor configuration and Chibikart could apply “static pressure” to something again. To get a good transition between sensored and sensorless, the sensors have to be aligned properly first (check out Equals Zero Designs’ page where I have an actually well documented example.) – and that’s all you need to do, not actually try and optimize their timing position.

This was, of course, the important part.

Now, the 12v PC fan could not handle 24 volts, so I just dropped a giant 40 ohm resistor in line so the fan only saw about 15v. This resistor surely dissipates more power than the fan actually removes…

With two motors on 40 amps, instead of on ~25 before, Chibikart2 is way more fun. Not, say, tinykart Black Edition level fun, but it is far more peppy. The small Colson wheels are starting to reach their traction limit.

I hit 1.1kW on indoors testing, and there is much room for improvement yet. Because the controllers are doubtlessly still running constant current before I run out of hallway, the power will only increase with vehicle speed.

Say, I haven’t garaged something properly in a long time (mostly because said garage was under repair construction this past summer). Maybe it’s time to take Chibikart back to its proving grounds.

Next, some of the ongoing facilities improvement projects that I have going on in the space! The place is kind of like I-95 around New England – always looking like someone’s working on it and the construction shifts every once in a while. I swear, though, it’ll be over soon – just like they say in Connecticut (In my six years in this area, I have never once driven through 95 in CT without hitting some kind of construction…)

First up, a full size Shopbot – the full 5 x 10, gifted by the Architecture department. I’ve been itching to have one of these for a while – with an 1/8″ carbide bit, they’re practically mechanical waterjets! Expect some Shopbottables to emerge on my end soon due to the “It’s the closest tool next to me and I don’t have to ask anyone to use it” effect. It will be very handy for producing Chibi-Mikuvan’s body panels since they’re all larger than what can be stuffed into the laser cutter.

Above, Media Lab students operate the machine as part of the MAS.863 “Build something big” week.

Next up, the legendary Form 1. Full disclosure: There’s four Form 1en in the space at the moment – this one is “The Lab’s”, and the rest belong to researchers and classes residing in it. Four. That’s more forms than Formlabs (okay, probably not), but the Form 1 density must be up there.

The Form is a SLA-like machine which can hit much higher resolutions, but the  material isn’t too strong – it’s an acrylic resin, so it has some mechanical strength, but does shatter and snap. Dat rez tho…

These are some of Brian Chan‘s insects. Check him out on Shapeways! I also printed the crab, lobster, and some other doodads from his collection.

Of course, with every 3D printer that makes it in here…

The  model is “Pillared Miku” though I used the version without built-in pillars – the Form software generates its own support lattice.

Now, moving up in the Expensivity scale is our latest acquisition:

 

An Objet24 (By Stratasys™)! This is just contributing to the slow rounding out of 3D printer technologies in the space. Objets are incredibly high resolution, very nice, and very expensive. This unit was purchased used from a local company for only $7,000, but you’d easily eat up that much per year in materials alone. The Objet Goo comes in 700 gram jugs that each cost $300-350 and up.

And this is the entry level machine.

The Objet technology combines SLA (light cured resin) with inkjet style nozzles so it can control the deposition very finely. No giant bubbling cauldron of goo here. It also has its own Windows XP computer built into it.

Now, I know XP is pretty much the OS that saw the Internet grow up with it, but this machine was built in 2011….

…and even worse, it requires a very specific network setup to talk to. Objet-Stratasys (ObSys? Stratajet?), I’m going to publicly shit on how bad the Objet communication infrastructure and software are. I should not have to configure a point-to-point LAN, disable Windows Updates, and disable firewalls just for it. The whole setup procedure gives me the vibe that they had to ship the machine and had 1 day left to write the drivers, so took whatever the developer’s computer was at the time and just made that the exact requirement. That, or given Objet is an Israeli company, probably just opens your computer up to direct monitoring by the Mossad.

I’m amazed I didn’t have to start Space Pinball and log into Pandora before the printer would communicate.

The slicing software is also slow, prone to crashing, and has an inconsistent UI. For such a beautiful piece of hardware, the software end of it seems so incredibly rigged.

Of course, the first thing to do with every 3D printer that makes it in here…..

Yeah. This was like a $30 Miku given how much of the material I used.

This corner of the room has been reconfigured to become what we now affectionately call “printrgartn”. The Form 1 is immediately off to the right, as is the Replicator 1. I’m trying to commission an Up for the lab (in supplement to my personal machine).

What’s absent, sadly, is a powder printer. I need to do some Powder Print Affirmative Action here.